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Free & open source · Now on Google Play
Your cycle,
entirely yours.
Inner Flare is a free, open-source cycle tracker that never leaves your device. No accounts, no cloud, no ads, no tracking of any kind. Just your data and your patterns.
On Google Play now. iOS is in App Store review.
What we build toward
Three things come before
Three things come before
anything else.
Every decision in Inner Flare (the database, the license, the roadmap) gets checked against this order. Nothing else is allowed to come first.
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Secure data, on your device only. Your cycle data is encrypted at rest and never leaves your phone unless you explicitly export it. There is no server to breach because there is no server.
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Free, forever, and open source. Inner Flare is FOSS-friendly by design: your device, your data, zero tracking, zero web access. The code is public so anyone can verify every claim on this page.
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Reproductive health belongs to everyone. Understanding your own cycle shouldn't require trusting a company with it. We believe the whole world benefits when people are empowered to track and understand their own reproductive health, on their own terms.
How it works
Built to be honest,
Built to be honest,
not clever.
No black-box AI, no dark patterns, no data model designed to be monetized later. Just a calm, capable tracker that does exactly what it says.
Predictions you can check
Cycle length, variability, and fertile-window estimates come from transparent statistics (the average of your own recent cycles), never an opaque AI model.
Your data, your file
Export a single, standard file whenever you want, to move to a new phone or just keep your own backup. No account required to create it, none to read it back.
Every card, your choice
Show, hide, or reorder anything on your dashboard. There's no "default everyone sees this" layout that can't be turned off.
Screens from the app
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One screen per day. Nothing is required. -
Averages show their sample size and spread. -
Turn cards off, reorder them, resize them. -
Locks again when you step away. -
One file, when you ask for it. Encryption optional.
Screens from Inner Flare 1.2 on iPhone, using made-up demo data.
Privacy by design
No cloud. No accounts.
No cloud. No accounts.
No web access at all.
Reproductive health data is some of the most sensitive information that exists. Inner Flare doesn't have the option to leak it, because it has no way to send it anywhere.
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Encrypted at rest, on-device only Your cycle data lives in an encrypted local database, unlocked with your device's biometrics where supported.
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No network access, by design The app requests no internet permission at all: this is enforced in CI, not just promised in a policy.
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Zero analytics or telemetry No crash reporters that phone home, no advertising identifiers, no tracking of any kind.
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Open source, so you don't have to trust us Every line is public. If a claim on this page is wrong, anyone can find it in the code and say so.
Why this exists
View source on GitHub
Reproductive health, without the trade-off.
Cycle tracking is one of the most common (and most surveilled) forms of health tracking there is. It shouldn't have to be a choice between understanding your body and keeping your data private.
Inner Flare is a sibling project to Health Flare, built on the same principle: the people using an app for their most sensitive health information deserve total control over where that information goes: for Inner Flare, that's nowhere but the device it's on.
We believe cycle and fertility awareness benefits everyone, not just the person tracking, and that empowerment starts with a tool people can actually trust. Being free and open source isn't a marketing line here; it's how that trust gets verified, by anyone, at any time.
Follow along, or dig in.
Inner Flare is on Google Play now, and the iOS version is in App Store review. Development stays in the open: star the repo to follow progress, open an issue with an idea, or read the code yourself. There's nothing hidden to find.
No accounts, no waitlist, no email required: the source is the invitation.
